This invention relates to a mandrel locking mechanism and, more particularly, to a mandrel utilized for the winding of webs at high speed.
One of the earliest automatic, continuous rewinders is seen in co-owned U.S. Pat. No. 2,769,600. These rewinders were adapted to operate without slow-down or interruption when a given retail-size web roll was completed. For this purpose, the winder was equipped with a turret which contained a plurality of mandrels, which were indexed in an orbit so as to have a mandrel ready to take up the winding operation when a previous mandrel had completed it, winding cycle.
Prior to entering into a winding cycle, the mandrel was ensleeved with a cardboard core. The core was equipped with adhesive for coupling the leading edge portion of the relatively flimsy web to the core. Further, the mandrel was equipped with locking lugs (sometimes referred to as "fingers" or "dogs") to fix the core both rotationally and axially to the mandrel. An improved mandrel for the early automatic, continuous machines is seen in co-owned U.S. Pat. Nos. 2,901,192 and 2,931,590.
With the advent of wider, higher speed rewinders in the 1960's, the earlier mandrels were considered inadequate and an improved mandrel, as shown in co-owned U.S. Pat. No. 3,331,565, was tried. However, this also was inadequate and the earlier version of the '192 patent was modified.
More particularly, the modification included a mechanism for adjusting the position of the core locking mechanism and the introduction of a second spring axially spaced from the original spring.
Over the years, this double spring construction presented many problems, particularly in the alignment of the locking lugs, the utilization of the adjustment feature and distortion of the locking mechanism.
These problems have been solved by the instant invention by providing separate means for adjusting the locking lug position and the spring pressure in a compact arrangement and also providing readily replaceable lugs arranged to properly grip cores while being constructed to remain in place under the high centrifugal forces generated by rotational speeds of several thousand revolutions per minute.
Other objects and advantages of the invention may been seen in the details of construction and operation as set forth hereinafter.